In Situ Hydrogels for Effective Treatment of Cancer: Strategies and Polymers Used

Cancer is a worldwide health ailment with no known boundaries in terms of mortality and occurrence rates, thus is one of the biggest threats to humankind. Hence, there is an absolute need to develop novel therapeutics to bridge the infirmities associated with chemotherapy and conventional surgical methodologies, including impairment of normal tissue, compromised drug efficiency and an escalation in side effects. In lieu of this, there has been a surge in curiosity towards the development of injectable hydrogels for cancer therapy because local administration of the active pharmaceutical agent offers encouraging advantages such as providing a higher effective dose at the target site, a prolonged retention time of drug, ease of administration, mitigation of dose in vivo, and improved patient compliance. Furthermore, due to their biocompatible nature, such systems can significantly reduce the side effects that occur on long-term exposure to chemotherapy. The present review details the most recent advancements in the in-situ gel forming polymers (natural and synthetic), polymeric cross-linking methodologies and in-situ gelling mechanisms, focusing on their clinical benefits in cancer therapy.